Magma ascent and degassing processes of the 2011 and 2017–18 eruptions of Shinmoedake in Kirishima volcano group, Japan, based on petrological characteristics and volatile content of magmas

Earth, Planets and Space

Table 2 Whole-rock compositions (in weight percent) of volcanic rocks from the 1716–17, 2011, and 2018 eruptions of the Shinmoedake volcano, 1235 eruption of the Ohachi volcano, and 7 ka eruption of the Takachihonomine volcano. Refer to Table 1 for sample names

Sample name	7 ka lava^a	1235S	1716-17GP^b	1716-17WP^b
Notes
SiO₂	53.63	53.58	57.82 (0.65)	63.01
TiO₂	0.89	0.80	0.75 (0.02)	0.72
Al₂O₃	19.06	19.16	17.55 (0.21)	16.56
FeOt	8.98	8.29	7.48 (0.33)	5.61
MnO	0.15	0.16	0.14 (0.01)	0.11
MgO	3.77	4.54	4.06 (0.24)	2.45
CaO	9.07	9.84	7.70 (0.18)	6.22
Na₂O	3.25	2.81	2.90 (0.09)	2.91
K₂O	1.21	0.81	1.59 (0.10)	2.42

Sample name	2011-2SGP^b	2011-2SWP^b	2011-3SGP^b	2011-4VB^b	2011-5VL^b	2011-7VL
Notes						5 fragments
SiO₂	57.87 (0.32)	63.24 (0.10)	57.28 (0.46)	57.73 (0.06)	57.36 (0.97)	57.55
TiO₂	0.71 (0.02)	0.06 (0.01)	0.74 (0.04)	0.72 (0.00)	0.71 (0.02)	0.71
Al₂O₃	17.48 (0.26)	16.66 (0.11)	17.33 (0.64)	17.41 (0.26)	17.58 (0.73)	17.11
FeOt	7.36 (0.22)	5.46 (0.04)	7.73 (0.55)	7.47 (0.13)	7.65 (0.30)	7.79
MnO	0.14 (0.01)	0.11 (0.00)	0.15 (0.01)	0.15 (0.01)	0.15 (0.01)	0.15
MgO	4.10 (0.18)	2.71 (0.07)	4.41 (0.49)	4.31 (0.26)	4.43 (0.36)	4.53
CaO	7.81 (0.15)	6.18 (0.15)	7.97 (0.19)	7.79 (0.07)	7.76 (0.14)	7.72
Na₂O	2.91 (0.04)	3.15 (0.00)	2.85 (0.13)	2.86 (0.03)	2.83 (0.08)	2.88
K₂O	1.60 (0.05)	2.44 (0.03)	1.54 (0.11)	1.57 (0.00)	1.52 (0.08)	1.57

Sample name	2018-1VGP	2018-2VGP	2018-2VS	2018-3BB1	2018-3BB2	2018-3BB3	2018-4L1	2018-4L2	2018-4L3	2018-4L4	2018-4L5
Notes		3 fragments	5 fragments	Porous	Porous	Lithic	Dark gray, lithic	Dark gray, lithic	Gray, porous	Dark gray, porous	Gray, porous
SiO₂	58.15	58.80	58.39	58.17	58.18	58.27	58.21	58.21	62.65	58.41	63.04
TiO₂	0.68	0.69	0.70	0.71	0.71	0.69	0.71	0.72	0.66	0.71	0.66
Al₂O₃	18.13	17.48	17.79	17.35	17.52	17.53	17.45	17.41	16.26	17.32	16.13
FeOt	6.71	6.86	6.89	7.29	7.09	7.05	7.19	7.18	5.78	7.13	5.70
MnO	0.12	0.13	0.13	0.14	0.14	0.14	0.14	0.14	0.12	0.14	0.12
MgO	3.92	3.97	3.94	4.13	3.98	4.10	4.04	4.17	2.91	4.09	2.87
CaO	7.79	7.43	7.64	7.60	7.76	7.60	7.66	7.57	6.12	7.55	5.94
Na₂O	2.94	2.93	2.88	2.95	2.94	2.96	2.94	2.96	3.09	2.97	3.09
K₂O	1.57	1.69	1.65	1.64	1.67	1.67	1.65	1.64	2.42	1.68	2.46

FeOt, total iron as FeO. The chemical compositions are recalculated to 100%
Chemical compositions of 1235S, 2011-7VL, 2018 eruption products were measured using XRF in this study. Analytical errors for each element are shown in Ishizuka et al. (2014)
^aChemical composition of lava of 7 ka eruption at Takachihonomine volcano is after Imura and Kobayashi (2001)
^bChemical compositions of 1716-17GP, 1716-17WP, 2011-2SGP and 2011-3SGP, 2011-2SWP, 2011-4VB and 2011-5VL are after Tomiya et al. (2013). Standard deviation of each analysis is also shown in parenthesis